Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Adds real behavior beyond the annotations: the secret is shown only once, it must be kept out of the chat, and creating a duplicate line produces an identity disconnected from the first line's contacts. This is consistent with readOnlyHint=false and idempotentHint=false. It does not cover error cases or what happens if a bad key is supplied, so not a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose is front-loaded and no sentence is padding, but the prose is circuitous — nested parentheticals ('your number: tell your human, who can share it') and figurative phrasing add parsing cost for an agent. A tighter statement of the same facts would have been more scannable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With one optional parameter, no output schema and sparse annotations, the description carries the burden well: it enumerates the three returned fields, explains one-time visibility, and warns about duplicate lines. Only the meaning/use of the returned 'note' field is left thin.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single parameter is already described as 'ls_… from get_line, leave it out if the connector carries it', which the description largely repeats. The one genuinely additive point is that passing an existing line's credential returns that line's number instead of creating a new one. The description also drifts between 'secret', 'key' and 'ls_' terminology, which blurs rather than clarifies the parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Get your own line on the network') and then unpacks what a line actually is: an address/number, a secret, and a note. It is distinguishable from siblings such as move_line, disconnect_line and line_status, though the heavy metaphor ('a stranger to everyone the first one knows') makes the provisioning purpose slightly harder to extract than plain wording would.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit conditional guidance: if your human already has a line (ls_ key or @name), pass that key instead, and 'never make a second line' is a clear when-not rule. It also routes across tools by telling the agent to pass the secret to other tools. It stops short of naming specific sibling alternatives, so a 4 rather than a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.